1. Field of the Invention
The present invention relates to a method of recording an image such that the image is exposed on light-sensitive material and then transferred to an image receiving material.
2. Description of the Related Art
Conventional image recording methods are known where an image on a light-sensitive material is exposed using optional exposure systems while the light-sensitive material is conveyed, the light-sensitive material is then superposed on the receiving material and those two materials are wound on the outer periphery of a heating drum, and the image is transferred to the receiving material by way of thermal development.
An image recording apparatus to which this kind of image recording method is applied provides an optical exposure system comprising, for example, a light source, a reflecting mirror and a lens that can be moved along a manuscript. Further, the image recording apparatus comprises conveyor rollers which convey the light-sensitive material to the exposure position.
When exposing an image on, for example, the original film, while emitting light from the light source, the light source and the lens move along the manuscript (that is, the emitted light is irradiated along the manuscript). At the same time, while the light-sensitive material is conveyed at a predetermined speed, reflected image light or transparent image light to the manuscript project upon the light-sensitive material, and the image is exposed on the light-sensitive material. The light-sensitive material on which the image is exposed is then carried to the thermal developing and transferring portion. The thermal developing and transferring portion comprises a heated drum and an endless pressure belt, and the light-sensitive material and the image receiving material are superposed and wound upon outer periphery of the drum. The light-sensitive material and the image receiving material in this superpositioned condition are heated together, heat developed and the image is transferred to the receiving material.
However, when the exposed light-sensitive material and the receiving material are superposed and wound upon the outer periphery of the heat drum as mentioned, the radius of the winding (in other words the radius of the curvature) depends upon the external radius of the drum and the thickness of the materials. The radius differs for the inner material and outer material upon the heat drum. Therefore, upon transfer of an image from the light-sensitive material to the receiving material, when the light-sensitive material is the outer layer, the image obtained after transfer will be smaller than the original exposure. On the other hand, the transferred image will be larger than the original exposure when the light-sensitive material is the inner layer. In either case, there is the problem that an error in transfer ratio appears, and in that is the circumferential direction of the drum a distorted image could be obtained on the image receiving material.
Making the outer radius of the heating drum large and thereby also making the winding radius of each material (upon winding, the radius of curvature) large, namely, making the winding radius difference between the materials small, necessitates large size device.